I have been using epen 2 for a number of years and despite it being more expensive than other brands p/month seems to be the only brand that doesn't give me acne breakouts. I have recently purchased a couple epen 3, From what i can make out thus far despite each pod holding more liquid than epen2 cartridges they do not seem to last any longer than the epen 2 cartridges and without a torch it's a bit of a task being able to see how much liquid you have left in the pod at any given time. Having said that i much prefer the idea of having the new pods as the mouthpiece, a nice shape and more hygienic too, a much improved coil as well. I have just ordered a variety of flavours in bulk and will assess them/the cost over time, thank you for the £2 per refill discount code i have to say that if you could throw more discounts like that in my direction i honestly wouldn't have any need to look anywhere else for liquid, A 50ml pod would be an interesting venture :)